Michael adducts from 6-nitrocoumarins and enaminoesters

Article abstract of DOI:10.1002/ardp.19953280110

Addition of the enaminoesters 2a-d to the 6-nitrocoumarins 1a-d gave 3 or 5. The aminocrotonic esters 2a,b underwent competitive addition of their C-4-methyl groups to yield 6a,b as by-products. Benzopyrano[3,4-c]pyridine derivatives 4b and 7-9 have been obtained from the adducts under various conditions. Some of the adducts have been converted by acidic hydrolysis into the amides 10 which have also been prepared directly by addition of ethylmalonamate to 1b-d.